🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STi Year: 2004 Codes Chassis Code: GDB Engine Code: EJ207 👋 Introduction Market Position Positioning: High-performance, rally-bred sports sedan targeted at enthusiasts and performance-oriented drivers. Competitive Analysis Competitors: Mitsubishi Lancer Evolution, Ford Focus RS, Audi S3, BMW 3 Series (performance variants). Key Features Drivetrain: Subaru's Symmetrical All-Wheel Drive (AWD) system with Driver Controlled Center Differential (DCCD). Engine: Legendary Subaru EJ207 2.0-liter turbocharged Boxer engine with twin-scroll turbocharger. Transmission: Close-ratio 6-speed manual transmission. Suspension: Performance-tuned suspension with inverted front struts. Braking: Performance Brembo brakes. 📋 Manual Details Coverage Areas Coverage Scope: Complete service and repair for the 2004 Subaru Impreza WRX STi Manual Type Type: Factory Service Manual / Workshop Manual Language Language: English Format File Format: PDF Print Quality Printability: Printable without restriction 📖 Manual Coverage Systems Covered Engine Mechanical: Detailed component disassembly, assembly, inspection, and repair procedures for the EJ207 STi engine. Fuel System: Fuel injection system, fuel pump, injectors, fuel pressure regulator, and fuel tank service. Emission Control: Evaporative emission control system (EVAP), catalytic converter, secondary air injection system (if applicable), and emissions related diagnostics. Intake System: Intake manifold, intercooler system, air intake ducting, and related sensors. Exhaust System: Exhaust manifold, downpipe, catalytic converter, muffler, and exhaust hangers. Cooling System: Radiator, coolant hoses, water pump, thermostat, coolant reservoir, and fan assembly. Lubrication System: Oil pump, oil pan, oil filter, oil cooler, and lubrication passages. Ignition System: Spark plugs, ignition coils, ignition timing, and ECU control. Speed Control System: Cruise control system operation, diagnostics, and component replacement. Transmission Manual: Operation, disassembly, assembly, inspection, and repair of the 6-speed DCCD (Driver Controlled Center Differential) manual transmission. Transmission AWD System: Center differential, rear differential, and transfer case service and maintenance. Brakes System: Brake fluid, calipers, rotors, pads, brake lines, ABS system components, and parking brake. Suspension System: Front and rear suspension components, struts, springs, control arms, sway bars, and alignment procedures. Steering System: Power steering pump, steering rack, tie rods, and steering column. Electrical System Charging: Alternator, battery, and charging circuit diagnostics. Electrical System Starting: Starter motor and related circuitry. Electrical System Lighting: Headlights, taillights, interior lights, fog lights, and related wiring. Electrical System Instruments: Instrument cluster, gauges, warning lights, and diagnostic trouble codes (DTCs). Electrical System Audio: Radio, speakers, and amplifier systems. Body And Interior: Door panels, seats, dashboard, trim pieces, and body hardware. Climate Control: HVAC system, air conditioning, heater core, blower motor, and controls. Safety Systems: Airbag system components and SRS wiring. Procedures Included Maintenance Tasks: Oil changes, filter replacements, fluid flushes, spark plug replacement, belt inspection and replacement. Troubleshooting: Diagnostic charts, symptom-based troubleshooting, and fault code interpretation. Repair Procedures: Step-by-step instructions for component removal, repair, and reinstallation. Diagnostic Testing: Procedures for testing sensors, actuators, and electrical circuits using multimeters and diagnostic tools. Torque Specifications: Detailed torque values for all critical fasteners. Diagrams And Illustrations: High-quality diagrams and step-by-step illustrations for all procedures. Wiring Diagrams: Comprehensive electrical wiring diagrams for all vehicle systems. Technical Depth Depth: Covers basic maintenance to complete engine and transmission overhauls, including complex diagnostics. 📊 Manual Specifications File Format Compatibility: Compatible with all versions of Windows and Mac operating systems. Reader Requirement: Requires Adobe PDF Reader. Binding Type Type: Digital Download ⚙️ Engine Specifications Primary Engine Engine Type: Horizontally-opposed (Boxer), turbocharged, intercooled, DOHC, 16-valve Displacement: 1994 cc (2.0 Liters) Bore X Stroke: 92.0 mm x 75.0 mm Compression Ratio: 8.0:1 Redline: 8000 RPM Performance Horsepower: 265 PS (261 hp; 195 kW) @ 6400 RPM Torque: 343 Nm (253 lb-ft) @ 4000 RPM Fuel System Fuel Delivery: Electronic Fuel Injection (EFI) with sequential port injection Fuel Type: Premium Unleaded Gasoline (95 RON or higher recommended) Engine Management ECU: Engine Control Unit (ECU) with specific STi tuning Turbocharger Type: Twin-scroll IHI VF37 Intercooler Type: Top-mounted air-to-air intercooler 🔧 Transmission Standard Type: 6-speed manual transmission Features Dccd: Driver Controlled Center Differential (DCCD) with manual and auto modes. Fluid Specifications Manual Transmission Fluid: Subaru Extra-S Gear Oil (75W-90 GL-5) or equivalent Fluid Capacities Manual Transmission Capacity: Approx. 2.3 liters (2.4 US quarts) 📐 Dimensions Exterior Length: 4405 mm (173.4 inches) Width: 1770 mm (69.7 inches) Height: 1410 mm (55.5 inches) Wheelbase: 2625 mm (103.3 inches) Weights Curb Weight: Approx. 1450 kg (3197 lbs) Gross Weight Rating: Approx. 1850 kg (4079 lbs) 🛡️ Safety Features Ratings NHTSA Front Impact: Not explicitly rated for this specific year/trim by NHTSA as a dedicated STi model in many markets. Standard Impreza models from this era received good ratings. IIHS Front Impact: Not explicitly rated for this specific year/trim by IIHS. Active Features ABS: Anti-lock Braking System (ABS) AWD: Symmetrical All-Wheel Drive (AWD) Dccd: Driver Controlled Center Differential (DCCD) for adjustable torque distribution. Passive Features Airbags: Front driver and passenger airbags, side airbags (optional/market dependent). Seatbelts: 3-point front and rear seatbelts with pretensioners and...